This study will attempt to define the role of herpesvirus infections in burned children. The only information available at the present time is contained in individual case reports, most of which concern burned adults. There is clear evidence that herpesviruses, namely herpes simplex virus, varicella-roster virus and cytomegalovirus, commonly complicate the course of immunosuppressed individuals and significantly alter their clinical outcome. The host immune mechanisms of burned individuals appear to be altered and the response to infectious agents may be impaired. Burned children who have a low incidence of previous exposure to cytomegalovirus receive large amounts of fresh blood, increasing the probability of acquiring such infections. By monitoring shedding of viruses and antibody responses to herpesvirus, varicella-roster virus, and cytomegalovirus, the rate of acquisition or reactivation will be established. Specific cell-mediated immunity to these three agents will also be measured in an attempt to identify abnormalities in host immunity which might explain the severity of these infections. Lymphocyte transformation and interferon production to specific viral antigens will be used as measures of specific cell-mediated immunity. Clinical correlations comparing the natural history of the viral infection to outcome will also be made. A new technique of measuring cell-mediated immunity to cytomegalovirus, namely an assay for lymphocyte cytotoxicity will be explored.